<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title>留言板</title>
        <style>
            .logo_box {
		position: absolute;
		background-color: #fff;
		width: 100px;
		height: 100px;
		border-radius: 100px;
		top: 100px;
		left: 46%;
		border: solid 5px #A68364;
		text-align: center;
	}
	.logo_img {
		margin-top: 20px;
	}
            .abc{
            color:rgb(255, 0, 0);
            }
        .xyz{
            color:rgb(148, 67, 67)
        }
        button{
            color:rgb(205, 152, 72)
        }
        </style>
        <script>
        function check(){
            var name = document.getElementById("name").value;
            var message = document.getElementById("message").value;
            if(name==""){
                alert("姓名不可为空")
                return;
            }
            if(message==""){
                alert("留言内容不可为空")
                return; 
            } }
        </script> 
    </head>
    <body>
        <div class="logo_box"><img class="logo_img" src="preview.jpg"></div>
        <div class="abc">
        <h1>请输入留言内容:</h1></div>
        <div class="xyz">
<form action="writeliuyan.php" method="post">
    姓名：<input type="text" id="username" name="username" placeholder="请输入姓名"><br>
    请留言:<textarea type="text" id="message" name="message" rows="10" cols="50" placeholder="请输入留言内容"></textarea><br></div>
<button onclick="check()">确认</button>
</form>
<form action="lookliuyan.php" method="post">
  <button>产看留言内容</button>
</form>
</body>
</html>